This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Vitamin K epoxide reductase (VKOR) generates vitamin K hydroquinone to sustain gamma-carboxylation of many blood coagulation factors. Coagulation factors require [unreadable]-carboxylation of glutamic acids for activation at sites of injury. The [unreadable]-carboxylase is driven by the oxidation of a vitamin K cofactor;the vitamin K epoxide reductase (VKOR) regenerates this cofactor. A disulfide is formed in VKOR during the latter reaction and is transferred to assist oxidative folding of nascent proteins. VKOR is the target of warfarin, the most commonly prescribed blood thinner used to treat and prevent heart attack, stroke, and other blood related diseases.